Shape measurement apparatus and method

Abstract

A shape measurement apparatus includes a work stage supporting a target substrate, a pattern-projecting section including a light source, a grating part partially transmitting and blocking light generated by the light source to generate a grating image and a projecting lens part making the grating image on a measurement target of the target substrate, an image-capturing section capturing the grating image reflected by the measurement target of the target substrate, and a control section controlling the work stage, the pattern-projecting section and the image-capturing section, calculating a reliability index of the grating image and phases of the grating image, which is corresponding to the measurement target, and inspecting the measurement target by using the reliability index and the phases. Thus, the accuracy of measurement may be enhanced.

What is claimed is: 
     
       1. A shape measurement apparatus comprising:
 a work stage supporting a target substrate including a device-mounting region and a pad region; 
 a pattern-projecting section comprising a light source, a grating part transmitting and blocking light generated by the light source to generate a grating image, and a projecting lens part making the grating image on a measurement target of the target substrate; 
 a camera capturing the grating images reflected by the measurement target of the target substrate; and 
 a control section board controlling the work stage, the pattern-projecting section and the camera to capture a plurality of phase shifted grating images, calculating a reliability index of the grating images based on one of the average intensity or the visibility of the plural grating images and calculating phases of the grating images, which correspond to the measurement target, inspecting the device-mounting region using the phases, and inspecting the pad region using the reliability index without using the calculated phases, wherein an amount of light of the reflected grating images is saturated for the pad region so as to be incapable of measuring the phases at the pad region. 
 
     
     
       2. The shape measurement apparatus of  claim 1 , wherein the shape measurement apparatus inspects a surface of a pad through the reliability index when the pad is the measurement target. 
     
     
       3. The shape measurement apparatus of  claim 2 , wherein the pad is to be electrically connected to an external device. 
     
     
       4. The shape measurement apparatus of  claim 2 , wherein the reliability index is at least one of a visibility and a signal to noise ratio. 
     
     
       5. The shape measurement apparatus of  claim 2 , wherein the control section board determines the pad is bad, when the reliability index is out of a setup value. 
     
     
       6. The shape measurement apparatus of  claim 5 , further comprising a subsidiary light source for inspecting the measurement target of the target substrate, and
 wherein the control section board determines that the pad is bad when light generated by the subsidiary light source is reflected by the pad and captured by the camera to form a two-dimensional image, and the pad is determined as bad in the two-dimensional image, even though the reliability index shows that the pad is good.